On Facebook, Williams explained she was sitting with her phone next to her when a stranger came up to them and began to chat. She said she had an “eerie feeling.”

“I kept watching him from the corner of my eye. Than when least expected low and behold this common petty thief grabbed my phone and swiftly left,” she wrote. “I looked at the chair, then shouted ‘Omg that dude took my phone!’”

Serena then got up from the table, ran past customers and chased the man out the door. She sprinted down the street and confronted him, the video shows.

She says he handed over the phone and told her: "I must have grabbed the wrong phone."

INSIDE EDITION showed the video to security expert Steve Kardian, who said: "She should have never chased him outside by herself. Grab staff, grab a friend. Don't dare to chase after him by yourself. He may have a weapon, he may be on drugs."

But while it may not have be the safest thing to do, Karidan says she handled it appropriately by having "non-threatening" body language.